Electrically heated evaporator unit for disposing of refrigerator system condensate



1956 A. R. COSTANTINI ETAL 3,230,530

ELECTRICALLY HEATED EVAPORATOR UNIT FOR DISPOSING 0F REFRIGERATOR SYSTEM CONDENSATE Filed May 5, 1964 5 ms 0 a m \sewk MkQQQQ l I w ,I 2 R? r Mas m as E wwmm m M a M mm 1 wd m w 1H1 m r Y A Md 2 o o K H T T G HA r Y B United States Patent ELECTRICALLY HEATED EVAPORATOR UNIT FOR DISPOSING OF REFRIGERATOR SYSTEM CONDENSATE Anthony R. Costantini, Lafayette Hill, and Anthony Di Angelus, Manon, Pa., assignors to Victory Metal Manufacturing Company, doing business as Victory Metal Manufacturing Corporation, Plymouth Meeting, Pa., a corporation of Pennsylvania Filed May 5, 1964, Ser. No. 365,104 1 Claim. (Cl. 62-275) This invention relates generally to moisture vaporizing apparatus, and more particularly relates to apparatus for vaporizing moisture accumulated by the action of cooling coils employed in refrigeration devices, to thereby dispose of condensed water vapor by passing the same back into the atmosphere exterior to the refrigerating device, and hence which eliminates the need for providing a waste water drain normally employed to carry off the condensation to a plumbing system.

A primary object of this invention is to provide a novel evaporator apparatus adapted for use with a refrigerating device and which materially simplifies the installation of the latter by making it unnecessary to provide a water run-off drainage system as is normally employed to carry off water vapor condensed by the refrigerating device during operation thereof.

Another object of this invention is to provide a novel evaporator unit which may be installed directly in a refrigerator apparatus during construction thereof or subsequent thereto, which evaporator unit includes a water receiver having a heater disposed therewithin which vaporizes water collected within the receiver, and in which the means for energizing the heater device is automatically operated by a float mechanism in accordance with the water level within the water receiver.

Still another object of this invention is to provide a novel evaporator unit as aforesaid which is so installed within a refrigerating device that the vaporized water is removed from the refrigerating device and prevented from entering the refrigerated regions of the refrigerator.

The foregoing and other objects of the invention will become clear from a reading of the following specification in conjunction with an examination of the appended drawings, wherein:

FIGURE 1 is a perspective view of the novel evaporator unit according to the invention having portions of the water receiver wall and a protective covering member sectioned away to reveal details of the interior construction of the unit; and

FIGURE 2 is a longitudinal vertical view partly in sec tion taken through the evaporator unit shown in perspective in FIGURE 1 as would be seen when viewed along the line 2--2 thereof.

In the several figures, like elements are denoted by like reference characters.

Referring now to the figures, it is observed that the water receiver designated generally as is formed from an open topped bottom pan 11 formed at its upper edge with a peripherally extending flange 12, and an open bottomed top pan 13 formed at its lower end with a peripherally extending flange 14. The bottom pan 11 and top pan 13 are substantially of the same size and shape, as are their flanges 12 and 14 so that the flange 14 directly overlies and seats smoothly downward upon the flange 12, the flanges then being peripherally sealed completely thereabout to form a water tight joint. The water receiver bottom pan is fitted with the condensate inlet pipe 15 secured to and opening into the bottom pan 11 proximate to the lower region of the latter, the inlet opening 16 lying always completely beneath the 3,280,580 Patented Oct. 25, 1966 surface level 16 of the condensate water 18 as is most clearly seen in the showing of FIGURE 2, and the top pan 13 is fitted with a short vent stack 19 through which the vaporized condensate leaves the water receiver 10. Secured to and extending upward from the rear wall of the top pan 13 as seen in FIGURE 1 is a mounting plate 20 apertured as at 21 by means of which the entire device may be secured to a convenient mounting bracket or wall.

Extending in a horizontal plane within the bottom pan 11 at a level approximately the same as the inlet opening 16 of the condensate pipe 15 is a U-shaped heater element 22 having threaded terminal ends 23 projected through holes in the near end wall of the bottom pan 11 and upon which are threaded the nuts 24 which fixedly secure the heater element 22 to the bottom pan 11 in the manner illustrated. The U-shaped heater element 22 may be of the Chromalox type manufactured by Edwin L. Wiegand and Company, of Pittsburgh, Pennsylvania, such heaters having an outer Inconel sheath within which extends an electrically energizable heater element which is electrically but not thermally insulated from the sheath by magnesium oxide powder and which extends outward through the terminal ends of the heater element as shown at 25 to terminal blocks 26 carrying connecting screws 27.

Welded or otherwise secured to the top pan 13 above the terminals of the heater element is a U-shaped bracket 28 to which is firedly secured a micro-switch 29 having an upwardly biased switch button 30 actuatable by an elongated flat resilient arm 31. When the elongated arm 31, and hence the switch button 30, is in its upper position the contacts of the micro-switch 29 are in a normally opened state. Since the heater element 22 and micro-switch are electrically connected in series circuit with a source of electrical energization by means of the electrical conductors 32, 33 and 34, the heater element 22 is in a deenergized state whenever the switch button 30 is in its up position. From consideration of FIGURE 2 it is observed that this deenergized condition of the heater element obtains when the water surface level 17 is at the illustrated lever so that the heater element 22 is covered with water and the inlet opening 16 of the condensate pipe 15 is below the surface level and thereby enable to function as a water sealed trap.

Disposed within the water receiver 10 is a pancake float 35 secured to a relatively long lever arm 36 which latter is fixedly secured to a horizontal pivot shaft 37 extending from front to rear through the top pan 13 proximate the upper end thereof and journalled through the front and rear walls, the forward end of the pivot shaft 37 being turned horizontally at substantially a right angle, as at 38, so as to overlie and rest upon the free end of the elongated resilient arm 31 of the micro-switch 29. Secured to and extending from the front and rear edges of the bottom pan 11 are brackets 39 vertically aligned with the end portions of the U-shaped bracket 28 so as to provide with the U-shaped bracket 28 supporting elements for the enclosure 40, which latter is secured in position by sheet metal screws 41. A strain relief 42 is fitted into the end wall of the enclosure 40 to take up any mechanical strains which may be imposed upon the electrical conductors 32 and 34 which pass therethrough.

The evaporator unit according to the invention operates in the following manner. Typically, the conditions illust-rated in FIGURE 2 would represent the low water level state of the condensate in the receiver 10 so that it may be assumed that the heater has just previously been deenergized due to the vaporization of water within the receiver with the attendant fall in level of the condensate and pancake float 35 resulting in opening of the cont acts of the micro-switch 29. The maintenance of a low but predetermined minimum water level as illustrated serves two purposes. First, by always insuring that the heater element 22 is completely covered by water, the maximum temperature of the heater is held to a value which avoids danger of burn-out and therefore insures a long and trouble free service life for the evaporator. Additionally, by insuring that the surface 17 of the condensate 18 always completely covers the inlet opening 16 of the condensate pipe 15, it is assured that none of the hot vapor created by operation of the heater 22 can pass upward through the condensate pipe 15 to regions of the refrigerator device. Excess humidity is thus prevented from build ing up within the refrigerated device and the temperature thereof is also more readily controlled.

Assuming now that the refrigeration system of the device becomes operative due to the temperature conditions within the refrigerated device, condensate is formed on the cooling coils of the refrigerating apparatus and is passed into the condensate inlet pipe 15 through which it flows downward into the water receiver of the evaporator unit. The condensate level therefore begins to rise and carry upward with it the float 35. The lever system including the long lever arm 36 and the front end 38 of the pivot shaft are thus caused to rotate so that the elongated resilient arm 31 of the micro-switch 29 begins to move downward and initiate depression of the switch button 30. Due to the small travel required to actuate the micro-switch 29 through its switch button 30, the surface level 17 of the condensate 18 need rise only by a very small amount in order to close the contacts of the microswitch and thereby energize the heater 22. Vaporization of the condensate of course does not immediately begin since the heater must first raise the temperature of the entire volume of condensate to the point where vaporization from the surface can occur, a certain length of time being required for this condition to result.

While the heating of the condensate is taking place, additional condensate is being continuously fed into the receiver through the inlet pipe so that the condensate level continues to rise within the receiver and the switch arm 31 is depressed further and further due to the continued rise of the float 35. The resilience of the elongated switch arm 31 permits it to flex under the downward urging of the pivot shaft front end lever arm 38 and thereby avoid breakage of any of the engaged parts. The rise of the condensate within the receiver It] continues until stabilization occurs due to the vaporization of condensate at a rate which is equal to the influx of additional condensate through the inlet pipe 15, the vaporized condensate passing upward and outward through the vent stack 19 of the receiver. The equilibrium state continues until the rate of vaporization exceeds the rate of condensate input to the receiver, at which point and thereafter the surface level 17 of the condensate begins to fall. The condensate level continues to fall until it is just very slightly higher than that illustrated in FIGURE 2, Whereupon the float 35 has dropped to a sufficiently low level as to raise the pivot shaft front end lever 38 high enough to permit the micro-switch button to move upward and open the contacts of the switch and thereby deenergize upward and open the contacts of the switch and thereby deenergize the heater element 22;

The vaporization of the condensate does not of course immediately terminate because the thermal mass of the heater element provides sufficient additional heat input to the condensate to cause continued vaporization thereof for a finite time after heater deenergization. The condensate surface 17 thus drops somewhat lower than the surface level at the instant of deenergization, but stabilizes at a final low level point which is still sufliciently high to insure the complete immersion of the heater element 22 within the condensate and to maintain the inlet opening of the condensate pipe 15 completely below the surface level to insure the liquid sealed trap condition previously described. When thereafter condensate again is discharged into the receiver, the previously described cycle will repeat.

While the evaporator unit according to the invention has been described as being utilized within a refrigerator device and operative to evaporate the water condensate which is formed by the extraction of humidity from the refrigerated air by the cooling coils of the refrigerating apparatus, nevertheless such an evaporator unit may be utilized for the vaporization of fluids other than water, as will readily be understood. Accordingly, having now described our invention in connection with a particularly illustrated embodiment thereof, it will be appreciated that variations and modifications of our invention may now occur from time to time to those persons normally skilled in the art without departing from the essential scope or spirit of our invention, and accordingly, it is intended to claim the same broadly as well as specifically as indicated by the appended claim.

What is claimed to be new and useful is;

In a refrigerator system having cooling coils which in operation produce condensate resulting in undesired moisture accumulating in the storage compartments of the refrigerator, the improvement comprising an automatic device operative in combination with said cooling coils to continuously receive the condensate and vaporize the same for discharge to atmosphere which includes a closed condensate receiver having a condensate inlet communicating with the interior of the receiver at a point adjacent the bottom of the receiver and a vapor outlet in the top of the receiver for discharge of vapor therefrom to atmosphere, an electrically energizable heater element disposed within said receiver in closely spaced relation to the bottom thereof, said heater element having terminals external of said receiver for connection in circuit with a source of electrical energization, switch means also external of said receiver connected in series with said heater element and its source of electrical energization, said switch means being normally biased into open condition and including a resilient switch arm operative to act against the normal bias of said switch means to close the same, float means disposed interiorly of the receiver for vertical movement in accordance with the rise and fall of the condensate level in the receiver, and pivoted lever arms respectively coupled to said float means and engageable with said switch arm, said lever arms being operable in unison to depress said switch arm and close the switch means to energize said heater element whenever said float means rises above a predetermined minimum level of condensate in said receiver and to release said switch arm under the normal opening bias of said switch means to deenergize said heater element whenever said float means drops to said predetermined minimum level of condensate, said lever arms being so mechanically interrelated to each other and to said float means and switch actuating arm as to maintain in said receiver a predetermined minimum volume of condensate at a level above said inlet suflicient to always maintain said heater element completely submerged in said condensate.

References Cited by the Examiner UNITED STATES PATENTS 1,758,922 5/1930 Berg 219-333 X 2,182,836 12/1939 Zu-mmach 219-362 2,211,407 8/1940 Christensen 219-272 2,236,359 3/1941 Armstrong 261-142 X 2,270,784 1/1942 Miller et al. 219-322 X 2,726,314 12/1955 Prain 219-322 X FOREIGN PATENTS 371,895 4/ 1932 Great Britain.

ANTHONY BARTIS, Primary Examiner. 

